US5972082A - Aqueous ink composition and ink-jet printing method using the same - Google Patents

Aqueous ink composition and ink-jet printing method using the same Download PDF

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US5972082A
US5972082A US08/848,192 US84819297A US5972082A US 5972082 A US5972082 A US 5972082A US 84819297 A US84819297 A US 84819297A US 5972082 A US5972082 A US 5972082A
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ink composition
aqueous ink
surfactant
ink
surface tension
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Masayuki Koyano
Ikuko Yamada
Akio Kojima
Kiyofumi Nagai
Masato Igarashi
Akiko Konishi
Hiroyuki Mochizuki
Takanori Tsuyuki
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Ricoh Co Ltd
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Ricoh Co Ltd
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Priority claimed from JP13273396A external-priority patent/JP3500484B2/en
Priority claimed from JP18405396A external-priority patent/JP3573878B2/en
Priority claimed from JP30574996A external-priority patent/JPH10130556A/en
Application filed by Ricoh Co Ltd filed Critical Ricoh Co Ltd
Assigned to RICOH COMPANY, LTD. reassignment RICOH COMPANY, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: IGARASHI, MASATO, KOJIMA, AKIO, KONISHI, AKIKO, KOYANO, MASAYUKI, MOCHIZUKI, HIROYUKI, NAGAI, KIYOFUMI, TSUYUKI, TAKANORI, YAMADA, IKUKO
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/30—Inkjet printing inks
    • C09D11/38—Inkjet printing inks characterised by non-macromolecular additives other than solvents, pigments or dyes

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  • the present invention relates to an aqueous ink composition, more particularly to an aqueous ink composition which comprises as the main components a colorant and a humectant.
  • the present invention also relates to a method of ink-jet printing method using the above-mentioned aqueous ink composition.
  • Ink-jet printers have been widely utilized in recent years because of the advantages of low noise and low running cost, and color printers capable of producing color images on a sheet of plain paper have also been placed on the market.
  • the ink can be readily loaded into an ink container at the initial stage (this performance will be hereinafter referred to as initial ink-loading performance), and the bubble generated in the ink container can be easily sent out therefrom (this performance will be hereinafter referred to as bubble-discharging performance). Further, the ink-refilling performance for the nozzle can be improved.
  • those alcohols have odor and have the problems of safety and stability during the long-term storage.
  • an aqueous ink composition comprising a styrene-acrylic acid copolymer is disclosed.
  • the reliability of ink-ejecting performance is unsatisfactory.
  • aqueous ink compositions each of which comprises a specific surfactant so as to improve the drying characteristics of the obtained images and minimize the deterioration of image quality, as disclosed in Japanese Laid-Open Patent Applications 6-107990 and 6-322303.
  • those ink compositions are employed for ink-jet printing, all of the previously mentioned requirements are not satisfied.
  • aqueous ink composition which can satisfy all the requirements of the ink composition for ink-jet printing, in particular, which can produce high quality ink images on plain paper with improved reliability of ink ejection.
  • a second object of the present invention is to provide an ink-jet printing method using the above-mentioned aqueous ink composition.
  • the first object of the present invention can be achieved by an aqueous ink composition comprising a colorant and a humectant.
  • This ink composition has a surface tension ⁇ of less than 50 mN/m when measured by a maximum bubble pressure method at 25° C., with a bubble frequency ⁇ of the aqueous ink composition being set at less than 1 Hz, and a surface tension ⁇ of more than 40 mN/m when measured by the maximum bubble pressure method at 25° C., with the bubble frequency ⁇ of the aqueous ink composition being set at more than 5 Hz.
  • this ink composition is suitable for ink-jet printing, in particular, capable of producing high quality ink images with high image density on a sheet of plain paper, without feathering or a so-called "strike through” phenomenon, with excellent reliability of ink-ejecting performance.
  • the second object of the present invention can be achieved by an ink-jet printing method for forming ink images on an image-receiving medium, comprising the step of ejecting the above-mentioned aqueous ink composition in the form of droplets according to recording signals at a recording frequency of 8 kHz or more.
  • FIG. 1 is a graph which shows the relationship between the bubble frequency and the surface tension of an aqueous ink composition No. 1 obtained in Example 1.
  • An aqueous ink composition according to the present invention comprises a colorant capable of being dispersed or dissolved in water, and a humectant, and shows a surface tension ( ⁇ ) of less than 50 mN/m at a bubble frequency ( ⁇ ) of less than 1 Hz, and a surface tension ( ⁇ ) of more than 40 mN/m at a bubble frequency ( ⁇ ) of more than 5 Hz when measured by a maximum bubble pressure method at 25° C.
  • the bubble frequency ⁇ of the ink composition and the surface tension ⁇ measured by the maximum bubble pressure method at 25° C. be in the relationship of:
  • the surface tension ( ⁇ ) of the aqueous ink composition is generally more than 20 mN/m when ⁇ 1 Hz, and less than 70 mN/m when ⁇ >5 Hz.
  • the surface tension ⁇ of the ink composition at a bubble frequency ⁇ of less than 1 Hz indicates a relatively static surface tension which is measured in a saturated time.
  • the surface tension ⁇ is less than 50 mN/m at a bubble frequency ⁇ of less than 1 Hz, the wettability of the ink flow path by the ink composition is sufficient and the ink ejecting performance is sufficiently reliable. If the surface tension ⁇ is 50 mN/m or more, the initial ink-loading performance and the bubble-discharging performance are considerably worsened.
  • the surface tension ⁇ of the ink composition at a bubble frequency ⁇ of more than 5 Hz indicates a dynamic surface tension which is measured in a short period of time.
  • the ink composition of the present invention can produce images with high reflection density on plain paper without feathering.
  • the surface tension ⁇ is 40 mN/m or less at a bubble frequency ⁇ of more than 5 Hz, the ink cannot uniformly spread on the surface of paper after the ink droplets are ejected on a sheet of plain paper.
  • the ink images thus obtained are free from edge sharpness. Further, in this case, the ink tends to penetrate into plain paper in the depth direction thereof, so that sufficient reflection density cannot be obtained.
  • both of the reliability of ink-ejecting performance and the image quality of ink images formed on paper are influenced under such condition of 1 ⁇ 5 Hz.
  • the surface tension ⁇ is controlled within the above-mentioned range under such condition of 1 ⁇ 5 Hz, the aqueous ink composition of the present invention can be provided with all the requirements for ink-jet printing.
  • the aqueous ink composition according to the present invention may further comprise at least the following surfactants A and B:
  • a surfactant A with a 0.1 wt. % aqueous solution of the surfactant A having a surface tension ⁇ A (mN/m) of less than 50 mN/m at a bubble frequency ⁇ A (Hz) of less than 1 Hz when measured by the maximum bubble pressure method at 25° C.
  • a surfactant B with a 0.1 wt. % aqueous solution of the surfactant B having a surface tension ⁇ B (mN/m) of more than 40 mN/m at a bubble frequency ⁇ B (Hz) of less than 1 Hz when measured by the maximum bubble pressure method at 25° C.
  • the surfactant A By the addition of the above-mentioned surfactant A, proper wettability of a material constituting the ink flow path by the obtained ink composition can be ensured when the ink composition is loaded into an ink-jet printer.
  • the surfactant B is added to the aqueous ink composition of the present invention, ink droplets can be ejected in a round form from the nozzle and uniformly spread on the surface of plain paper so as to form sharp picture elements.
  • the image quality can be upgraded without impairing the initial ink-loading performance and bubble-discharging performance by using appropriate surfactants A and B in combination.
  • the above-mentioned surfactant A be selected from the group consisting of a polyoxyethylene alkyl ether acetate of formula (I):
  • R 1 is an alkyl group having 6 to 14 carbon atoms, which may be branched, m is an integer of 3 to 12, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and a dialkyl sulfosuccinate of formula (II): ##STR1## wherein R 2 is an alkyl group having 5 to 7 carbon atoms, which may be branched, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation.
  • polyoxyethylene alkyl ether acetate of formula (I) are as follows: ##STR2##
  • dialkyl sulfosuccinate of formula (II) are as follows: ##STR3##
  • the above-mentioned surfactant B be a nonionic surfactant.
  • nonionic surfactants having an ethylene oxide chain in the molecular structure thereof for example, polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether are preferably employed.
  • the humectant for use in the ink composition a nitrogen-containing heterocyclic compound and/or a polyhydric alcohol may be employed.
  • the humectant comprise at least one compound selected from the group consisting of 2-pyrrolidone, diethylene glycol and glycerin.
  • the ratio by weight of diethylene glycol to glycerin may be in the range of 1/1 to 5/1, and the weight ratio by weight of 2-pyrrolidone to the mixture of diethylene glycol and glycerin be in the range of 0/1 to 1/0.
  • the fibers of paper can be uniformly dyed.
  • the colorant for use in the aqueous ink composition according to the present invention comprise at least one compound selected from the group consisting of the compounds formulae (III), (IV) and (V).
  • W is --OH group and X is --NH 2 group, or W is --NH 2 group and X is --OH group
  • Q 1 is a hydrogen atom or --SO 3 M group, in which M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation;
  • Q 2 is a hydrogen atom or --COOM group
  • Q 3 is a hydrogen atom, --COOM group or --SO 3 M group
  • Q 4 is a hydrogen atom, --CH 2 COOM group or --CH 2 CH 2 COOM group
  • M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and ##STR6## wherein W is --OH group and X is --NH 2 group, or W is --NH 2 group and X is --OH group, Y and Z are each independently --OH group or --NR 3 R 4 group, Q 5 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, --COOM group, --SO 3 M group or --NR 3 R 4 group, and Q 6 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, --COOM group or --SO 3 M group,
  • M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and R 3 and R 4 are each independently a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, or R 3 and R 4 may form a substituted or unsubstituted five-membered or six-membered ring in combination with the nitrogen atom.
  • the solubility stability is excellent, so that the image with high image density and improved color tone can be obtained.
  • the aqueous ink composition of the present invention comprise the surfactant A in an amount of 0.05 to 1.0 wt. %, the surfactant B in an amount of 0.05 to 5.0 wt. %, the humectant in an amount of 1 to 20 wt. %, and the colorant in an amount of 1 to 10 wt. %, of the total weight of the aqueous ink composition.
  • excellent properties for ink-jet printing can be imparted to the ink composition.
  • the formulation for the aqueous ink composition may be adjusted so as to have a contact angle of 40° or more with respect to plain paper and a contact angle of 50° or less with respect to a material constituting the ink flow path of the ink-jet printer, when measured at 25° C.
  • the formulation for the aqueous ink composition can be controlled so that the contact angle of the aqueous ink composition with the material constituting the ink flow path may be 50° or less without the addition of some alcohols to the formulation.
  • the ink flow path can be properly wetted with the aqueous ink composition, with the result that the formation of high quality images can be achieved without lowering the reliability of ink-ejecting performance.
  • an ink-jet printing method for forming ink images on an image-receiving medium using the above-mentioned aqueous ink composition.
  • Such an ink-jet printing method comprises the step of ejecting an aqueous ink composition in the form of droplets according to recording signals at a recording frequency of 8 kHz or more.
  • the aqueous ink composition of the present invention can cope with high recording frequency, so that high speed printing can be achieved.
  • the aqueous ink composition be deposited on the image-receiving medium with a deposition amount of 2.5 to 25 g/m 2 when the image-receiving medium is a sheet of plain paper.
  • excellent image quality can be obtained.
  • the aqueous ink composition of the present invention comprises water as a liquid medium.
  • humectants such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, and 3-methylpentane-1,3,5-triol; alkyl ethers derived from polyhydric alcohols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
  • the aqueous ink composition may further comprise a penetrating agent including the above-mentioned surfactants A and B.
  • the penetrating agent are anionic surfactants such as polyoxyethylene alkyl ether acetate, and dialkylsulfosuccinate having an alkyl chain with 5 to 7 carbon atoms, which may be branched; nonionic surfactants such as acetylene glycol, polyoxyethylene nonylphenyl ether, and polyoxyethylene alkyl ether; alkyl ethers or aryl ethers derived from polyhydric alcohols such as diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoaryl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, and tetraethylene glycol chlorophenyl ether; fluorochemical surfactants; silicone-based surfactants; and lower alcohols such as ethanol and 2-propanol.
  • anionic surfactants such as polyoxyethylene alkyl ether acetate, and
  • the above-mentioned compounds (III) to (V) may be used in combination with other colorants such as water-soluble dyes and pigments when necessary.
  • the water-soluble dyes for use in the present invention which are divided into the following groups in accordance with the color index number, an acid dye, a direct dye, a basic dye, a reactive dye and a food dye, have water-resistance and light-resistance. Those dyes may be contained in the aqueous ink composition so long as the objects of the present invention are not impaired.
  • Examples of the pigment serving as the colorant in the aqueous ink composition of the present invention include organic pigments such as azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perylene pigments isoindolenone pigments, Aniline Black, azomethine pigments, Rhodamine B lake pigments, and carbon black; and inorganic pigments such as iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, prussian blue, cadmium red, chrome yellow, and metal powder.
  • organic pigments such as azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perylene pigments isoindolenone pigments, An
  • aqueous ink composition may further comprise a pigment dispersant.
  • pigment dispersant for use in the present invention are natural hydrophobic polymers, for example, vegetable polymers such as gum arabic, tragacanth gum, guar gum, karaya gum, locust bean gum, arabinogalactan, pectin, and quince seed starch; seaweed polymers such as alginic acid, carrageenan, and agar; animal polymers such as gelatin, casein, albumin, and collagen; microbial polymers such as xanthene, and dextran; semisynthetic hydrophobic polymers, for example, cellulose polymers such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose; starch polymers such as starch sodium glycolate, and starch sodium phosphate; and seaweed-based polymers such as sodium alginate, and propyleneglycol alginate; and synthetic hydrophobic polymers, for example, vinyl polymers such as polyvinyl
  • the aqueous ink composition of the present invention may further comprise conventionally known additives such as an antiseptic agent, a mildewproofing agent, a pH adjustor, a chelate reagent, a corrosion inhibitor and a clogging preventing agent.
  • additives such as an antiseptic agent, a mildewproofing agent, a pH adjustor, a chelate reagent, a corrosion inhibitor and a clogging preventing agent.
  • sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, and sodium pentachlorophenol can be employed as the antiseptic agents and mildewproofing agents.
  • any materials that is capable of adjusting the obtained aqueous ink composition to pH7 or more without having no adverse effect on the ink composition can freely be employed as the pH adjustors in the present invention.
  • Examples of the pH adjustor for use in the present invention are amines such as diethanolamine and triethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; other hydroxides such as ammonium hydroxide, quaternary ammonium hydroxide and quaternary phosphonium hydroxide; and carbonates of alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate.
  • amines such as diethanolamine and triethanolamine
  • hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide
  • other hydroxides such as ammonium hydroxide, quaternary ammonium hydroxide and quaternary phosphonium hydroxide
  • carbonates of alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate.
  • Examples of the chelate reagent for use in the aqueous ink composition of the present invention include sodium ethylene diamine tetraacetate, sodium nitrilotriacetate, sodium hydroxyethyl ethylene diamine triacetate, sodium diethylene triamine pentaacetate, and sodium uramil diacetate.
  • corrosion inhibitor examples include acid sulfite, sodium thiosulfate, ammon thiodiglycollic acid, diisopropyl ammonium nitrite, pentaerythritol tetranitrate, and dicyclohexyl ammonium nitrite.
  • Examples of the clogging preventing agent are urea and urea derivatives such as hydroxyethylurea.
  • aqueous ink composition of the present invention may further comprise a water-soluble ultraviolet absorbing agent and a water-soluble infrared absorbing agent according to the application of the ink composition.
  • the above mixture was cooled to room temperature, and the pH of the mixture was adjusted to the range of 9 to 10 by the addition of 10% aqueous solution of lithium hydroxide.
  • the thus obtained mixture was filtered through a Teflon filter of 0.22 ⁇ m, so that an aqueous ink composition No. 1 according to the present invention was obtained.
  • the surface tension ( ⁇ ) of the above-prepared aqueous ink composition No. 1 was measured in the bubble frequency ( ⁇ ) range of 0.5 to 7 Hz at 25° C.
  • FIG. 1 is a graph which shows the relationship between the surface tension ( ⁇ ) and the bubble frequency ( ⁇ ) of the aqueous ink composition No. 1.
  • Example 1 The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
  • the surface tension ( ⁇ ) of the above-prepared aqueous ink composition No. 2 was measured in the same manner as in Example 1.
  • Example 1 The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
  • the surface tension ( ⁇ ) of the above-prepared aqueous ink composition No. 3 was measured in the same manner as in Example 1.
  • Example 1 The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
  • the surface tension ( ⁇ ) of the above-prepared aqueous ink composition No. 4 was measured in the same manner as in Example 1.
  • Example 1 The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
  • the surface tension ( ⁇ ) of the above-prepared aqueous ink composition No. 5 was measured in the same manner as in Example 1.
  • the surface tension ( ⁇ ) of the above-prepared comparative aqueous ink composition No. 1 was measured in the same manner as in Example 1.
  • the surface tension ( ⁇ ) of the above-prepared comparative aqueous ink composition No. 2 was measured in the same manner as in Example 1.
  • the procedure for preparation of the aqueous ink composition No. 4 in Example 4 was repeated except that a mixture of 2-pyrrolidone in an amount of 6 wt. %, diethylene glycol in an amount of 3 wt. % and glycerin in an amount of 1 wt. % used in the formulation for the ink composition No. 4 in Example 4 was replaced by diethylene glycol monobutyl ether in an amount of 10 wt. %.
  • the surface tension ( ⁇ ) of the above-prepared comparative aqueous ink composition No. 3 was measured in the same manner as in Example 1.
  • the procedure for preparation of the aqueous ink composition No. 5 in Example 5 was repeated except that the amount of the Compound (I-1) serving as the surfactant A used in the formulation for the ink composition No. 5 in Example 5 was changed from 0.1 wt % to 2 wt. %.
  • the surface tension ( ⁇ ) of the above-prepared comparative aqueous ink composition No. 4 was measured in the same manner as in Example 1.
  • Each ink composition was separately filled into an ink-jet printer having a nozzle with a diameter of 32 ⁇ m and a density of 600 dpi.
  • the nozzle was caused to eject the ink composition by the application of pressure thereto at a recording frequency of 12 kHz, utilizing the action of piezoelectric element of PZT of a laminated material.
  • the ink deposition amount was about 20 g/m 2 in the solid image portion.
  • the printing operation was continuously carried out without a cleaning sequence of purging, vacuuming and wiping. Then, the printing operation was stopped for 24 hours. When the printing operation was again started after intermission of 24 hours, it was examined whether the weight of an ink droplet ejected from the nozzle was changed or not, and the ejecting direction was deviated or not. The reliability of ink-ejecting performance was evaluated on the following scale:
  • the surface tension of the aqueous ink composition is controlled as mentioned above. Therefore, when the aqueous ink composition of the present invention is used for ink-jet printing, the initial ink-loading performance and bubble-discharging performance are excellent due to sufficient wettability of the ink flow path by the ink composition. In addition, when ink images are formed on plain paper using the aqueous ink composition according to the present invention by ink-jet printing method, high quality images can be obtained because of proper penetrating properties of the ink composition into plain paper and wettability of plain paper by the ink composition.
  • Japanese Patent Application No. 08-132733 filed Apr. 30, 1996, Japanese Patent Application No. 08-184053 filed Jun. 25, 1996, and Japanese Patent Application No. 08-305749 filed Oct. 31, 1996 are hereby incorporated by reference.

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Abstract

An aqueous ink composition contains a colorant and a humectant, and has a surface tension γ of less than 50 mN/m when measured by a maximum bubble pressure method at 25° C., with a bubble frequency ν of the aqueous ink composition being set at less than 1 Hz, and a surface tension γ of more than 40 mN/m when measured by the maximum bubble pressure method at 25° C., with the bubble frequency ν of the aqueous ink composition being set at more than 5 Hz. In addition, an ink-jet printing method for forming ink images on an image-receiving medium has the step of ejecting the above-mentioned aqueous ink composition in the form of droplets according to the recording signals at a recording frequency of 8 kHz or more.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an aqueous ink composition, more particularly to an aqueous ink composition which comprises as the main components a colorant and a humectant.
The present invention also relates to a method of ink-jet printing method using the above-mentioned aqueous ink composition.
2. Discussion of Background
Ink-jet printers have been widely utilized in recent years because of the advantages of low noise and low running cost, and color printers capable of producing color images on a sheet of plain paper have also been placed on the market.
However, it is extremely difficult to obtain a color ink composition which is satisfactory with respect to the requirements such as the following: image density, color reproduction, water-resistance, light-resistance, drying characteristics, blurring of images and the strike-through phenomenon, and the reliability of ink-ejection. In particular, it is necessary to control not only the wettability of plain paper by the ink composition and the penetration properties of the ink into the paper, but also the wettability of a material constituting the flow path for ink composition in the ink-jet printer (hereinafter referred to as the ink flow path) by the ink composition and the penetration properties of the ink into the above-mentioned material for path. Therefore, the formulation for the aqueous ink is of great importance because the above-mentioned physical properties are determined by the ink composition.
The addition of an alkyl alcohol having 1 to 4 carbon atoms, and a monohydric alcohol having 4 carbon atoms or less, to the formulation for the ink composition is proposed as disclosed in Japanese Laid-Open Patent Applications 6-100808 and 6-166841, respectively. Such alcohols are added to the ink composition not only to improve the image quality, but also to ensure proper wettability of the material constituting the ink flow path by the ink composition. When such proper wettability of the ink flow path by the ink composition is obtained, the ink can be readily loaded into an ink container at the initial stage (this performance will be hereinafter referred to as initial ink-loading performance), and the bubble generated in the ink container can be easily sent out therefrom (this performance will be hereinafter referred to as bubble-discharging performance). Further, the ink-refilling performance for the nozzle can be improved. However, those alcohols have odor and have the problems of safety and stability during the long-term storage.
In Japanese Laid-Open Patent Application 6-136306, an aqueous ink composition comprising a styrene-acrylic acid copolymer is disclosed. However, when the ink-jet printer with a stationary-type head is supplied with the above-mentioned ink composition, the reliability of ink-ejecting performance is unsatisfactory.
The inventors of the present invention have already proposed aqueous ink compositions, each of which comprises a specific surfactant so as to improve the drying characteristics of the obtained images and minimize the deterioration of image quality, as disclosed in Japanese Laid-Open Patent Applications 6-107990 and 6-322303. However, even though those ink compositions are employed for ink-jet printing, all of the previously mentioned requirements are not satisfied. At present there is an increasing demand for further improvement of the image density and reduction of image blurring.
SUMMARY OF THE INVENTION
Accordingly, it is therefore a first object of the present invention to provide an aqueous ink composition which can satisfy all the requirements of the ink composition for ink-jet printing, in particular, which can produce high quality ink images on plain paper with improved reliability of ink ejection.
A second object of the present invention is to provide an ink-jet printing method using the above-mentioned aqueous ink composition.
The first object of the present invention can be achieved by an aqueous ink composition comprising a colorant and a humectant. This ink composition has a surface tension γ of less than 50 mN/m when measured by a maximum bubble pressure method at 25° C., with a bubble frequency ν of the aqueous ink composition being set at less than 1 Hz, and a surface tension γ of more than 40 mN/m when measured by the maximum bubble pressure method at 25° C., with the bubble frequency ν of the aqueous ink composition being set at more than 5 Hz. Therefore, this ink composition is suitable for ink-jet printing, in particular, capable of producing high quality ink images with high image density on a sheet of plain paper, without feathering or a so-called "strike through" phenomenon, with excellent reliability of ink-ejecting performance.
The second object of the present invention can be achieved by an ink-jet printing method for forming ink images on an image-receiving medium, comprising the step of ejecting the above-mentioned aqueous ink composition in the form of droplets according to recording signals at a recording frequency of 8 kHz or more.
BRIEF DESCRIPTION OF THE DRAWING
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing, wherein:
FIG. 1 is a graph which shows the relationship between the bubble frequency and the surface tension of an aqueous ink composition No. 1 obtained in Example 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An aqueous ink composition according to the present invention comprises a colorant capable of being dispersed or dissolved in water, and a humectant, and shows a surface tension (γ) of less than 50 mN/m at a bubble frequency (ν) of less than 1 Hz, and a surface tension (γ) of more than 40 mN/m at a bubble frequency (ν) of more than 5 Hz when measured by a maximum bubble pressure method at 25° C.
In the maximum bubble pressure method, when gas is fed to a capillary tip which is perpendicularly immersed in a liquid to a known depth, bubbles are generated. The surface tension γ can be obtained from the measurement of the maximum pressure required to release the bubble. This method for measuring the surface tension is mentioned in "Colloids and Surfaces", vol. 44 (1990), pages 101-117.
According to the present invention, it is preferable that the bubble frequency ν of the ink composition and the surface tension γ measured by the maximum bubble pressure method at 25° C. be in the relationship of:
γ<46 mN/m when ν<1 Hz,
2.5 ν+30.5≦γ≦2.5 ν+43.5 when 1≦ν≦5 Hz, and
γ>43 mN/m when ν>5 Hz.
In the present invention, the surface tension (γ) of the aqueous ink composition is generally more than 20 mN/m when ν<1 Hz, and less than 70 mN/m when ν>5 Hz.
The surface tension γ of the ink composition at a bubble frequency ν of less than 1 Hz indicates a relatively static surface tension which is measured in a saturated time. In the present invention, since the surface tension γ is less than 50 mN/m at a bubble frequency ν of less than 1 Hz, the wettability of the ink flow path by the ink composition is sufficient and the ink ejecting performance is sufficiently reliable. If the surface tension γ is 50 mN/m or more, the initial ink-loading performance and the bubble-discharging performance are considerably worsened.
The surface tension γ of the ink composition at a bubble frequency ν of more than 5 Hz indicates a dynamic surface tension which is measured in a short period of time. In the present invention, since the surface tension γ is more than 40 mN/m at a bubble frequency ν of more than 5 Hz, the ink composition of the present invention can produce images with high reflection density on plain paper without feathering. To be more specific, if the surface tension γ is 40 mN/m or less at a bubble frequency ν of more than 5 Hz, the ink cannot uniformly spread on the surface of paper after the ink droplets are ejected on a sheet of plain paper. The ink images thus obtained are free from edge sharpness. Further, in this case, the ink tends to penetrate into plain paper in the depth direction thereof, so that sufficient reflection density cannot be obtained.
Further, both of the reliability of ink-ejecting performance and the image quality of ink images formed on paper are influenced under such condition of 1≦ν≦5 Hz. When the surface tension γ is controlled within the above-mentioned range under such condition of 1≦ν≦5 Hz, the aqueous ink composition of the present invention can be provided with all the requirements for ink-jet printing.
The aqueous ink composition according to the present invention may further comprise at least the following surfactants A and B:
(i) a surfactant A, with a 0.1 wt. % aqueous solution of the surfactant A having a surface tension γA (mN/m) of less than 50 mN/m at a bubble frequency νA (Hz) of less than 1 Hz when measured by the maximum bubble pressure method at 25° C., and
(ii) a surfactant B, with a 0.1 wt. % aqueous solution of the surfactant B having a surface tension γB (mN/m) of more than 40 mN/m at a bubble frequency νB (Hz) of less than 1 Hz when measured by the maximum bubble pressure method at 25° C.
By the addition of the above-mentioned surfactant A, proper wettability of a material constituting the ink flow path by the obtained ink composition can be ensured when the ink composition is loaded into an ink-jet printer. When the surfactant B is added to the aqueous ink composition of the present invention, ink droplets can be ejected in a round form from the nozzle and uniformly spread on the surface of plain paper so as to form sharp picture elements. Thus, the image quality can be upgraded without impairing the initial ink-loading performance and bubble-discharging performance by using appropriate surfactants A and B in combination.
It is preferable that the above-mentioned surfactant A be selected from the group consisting of a polyoxyethylene alkyl ether acetate of formula (I):
R.sup.1 --O--(CH.sub.2 CH.sub.2 O).sub.m --CH.sub.2 COOM   (I)
wherein R1 is an alkyl group having 6 to 14 carbon atoms, which may be branched, m is an integer of 3 to 12, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and a dialkyl sulfosuccinate of formula (II): ##STR1## wherein R2 is an alkyl group having 5 to 7 carbon atoms, which may be branched, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation.
When such a specific surfactant A is employed, the reliability of ink-ejection can be further increased.
Specific examples of the polyoxyethylene alkyl ether acetate of formula (I) are as follows: ##STR2##
Specific examples of the dialkyl sulfosuccinate of formula (II) are as follows: ##STR3##
Further, it is preferable that the above-mentioned surfactant B be a nonionic surfactant. In particular, nonionic surfactants having an ethylene oxide chain in the molecular structure thereof, for example, polyoxyethylene alkyl ether and polyoxyethylene alkylphenyl ether are preferably employed.
When such a specific surfactant B is chosen for the ink composition, the wettability of plain paper by the ink and the penetrating properties of ink into plain paper are further improved.
As the humectant for use in the ink composition, a nitrogen-containing heterocyclic compound and/or a polyhydric alcohol may be employed. To be more specific, it is preferable that the humectant comprise at least one compound selected from the group consisting of 2-pyrrolidone, diethylene glycol and glycerin. In the case where those are used in combination, the ratio by weight of diethylene glycol to glycerin may be in the range of 1/1 to 5/1, and the weight ratio by weight of 2-pyrrolidone to the mixture of diethylene glycol and glycerin be in the range of 0/1 to 1/0.
Since such a specific humectant has excellent solubility stability, the fibers of paper can be uniformly dyed.
It is preferable that the colorant for use in the aqueous ink composition according to the present invention comprise at least one compound selected from the group consisting of the compounds formulae (III), (IV) and (V). ##STR4## wherein W is --OH group and X is --NH2 group, or W is --NH2 group and X is --OH group, and Q1 is a hydrogen atom or --SO3 M group, in which M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; ##STR5## wherein Q2 is a hydrogen atom or --COOM group, Q3 is a hydrogen atom, --COOM group or --SO3 M group, and Q4 is a hydrogen atom, --CH2 COOM group or --CH2 CH2 COOM group,
in which M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and ##STR6## wherein W is --OH group and X is --NH2 group, or W is --NH2 group and X is --OH group, Y and Z are each independently --OH group or --NR3 R4 group, Q5 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, --COOM group, --SO3 M group or --NR3 R4 group, and Q6 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, --COOM group or --SO3 M group,
in which M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and R3 and R4 are each independently a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, or R3 and R4 may form a substituted or unsubstituted five-membered or six-membered ring in combination with the nitrogen atom.
When the colorant comprises the above-mentioned specific compounds, the solubility stability is excellent, so that the image with high image density and improved color tone can be obtained.
Specific examples of the compound of formula (III) in the form of a free acid are as follows: ##STR7##
Specific examples of the compound of formula (IV) in the form of a free acid are as follows: ##STR8##
Specific examples of the compound of formula (V) in the form of a free acid are as follows: ##STR9##
It is preferable that the aqueous ink composition of the present invention comprise the surfactant A in an amount of 0.05 to 1.0 wt. %, the surfactant B in an amount of 0.05 to 5.0 wt. %, the humectant in an amount of 1 to 20 wt. %, and the colorant in an amount of 1 to 10 wt. %, of the total weight of the aqueous ink composition. Thus, excellent properties for ink-jet printing can be imparted to the ink composition.
When the aqueous ink composition of the present invention is used for ink-jet printing method in such a manner that a nozzle of the ink-jet printer is caused to eject the ink composition onto plain paper in accordance with the recording signals, in a preferred embodiment the formulation for the aqueous ink composition may be adjusted so as to have a contact angle of 40° or more with respect to plain paper and a contact angle of 50° or less with respect to a material constituting the ink flow path of the ink-jet printer, when measured at 25° C.
Conventionally, when the contact angle of an ink composition with plain paper is controlled to 40° or more, there can be formed on plain paper high quality ink image with minimum feathering and high reflection density. However, the ink flow path in the ink-jet printer cannot be readily wetted with the above-mentioned ink composition. As a result, this has an adverse effect on the initial ink-loading performance and the bubble-discharging performance of the ink composition, and the reliability of ink ejection will be lowered.
According to the present invention, however, the formulation for the aqueous ink composition can be controlled so that the contact angle of the aqueous ink composition with the material constituting the ink flow path may be 50° or less without the addition of some alcohols to the formulation. Thus, the ink flow path can be properly wetted with the aqueous ink composition, with the result that the formation of high quality images can be achieved without lowering the reliability of ink-ejecting performance.
According to the present invention, there can be provided an ink-jet printing method for forming ink images on an image-receiving medium using the above-mentioned aqueous ink composition. Such an ink-jet printing method comprises the step of ejecting an aqueous ink composition in the form of droplets according to recording signals at a recording frequency of 8 kHz or more.
Namely, the aqueous ink composition of the present invention can cope with high recording frequency, so that high speed printing can be achieved.
In the above-mentioned ink-jet printing method it is preferable that the aqueous ink composition be deposited on the image-receiving medium with a deposition amount of 2.5 to 25 g/m2 when the image-receiving medium is a sheet of plain paper. Thus, excellent image quality can be obtained.
The aqueous ink composition of the present invention comprises water as a liquid medium. To impart the desired physical properties to the obtained aqueous ink composition, to prevent the ink composition from drying, and to improve the solubility stability of the compounds employed in the ink composition, not only the above-mentioned humectants, but also the following organic solvents can be employed alone or in combination: polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, and 3-methylpentane-1,3,5-triol; alkyl ethers derived from polyhydric alcohols such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether; aryl ethers derived from polyhydric alcohols such as ethylene glycol monophenyl ether, and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, and ε-caprolactam; amides such as formamide, N-methylformamide, and N,N-dimethylformamide; amines such as monoethanol amine, diethanol amine, triethanol amine, monoethylamine, diethyl amine, and triethyl amine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane, and thiodiethanol; propylene carbonate; ethylene carbonate; and γ-butyrolactone.
The aqueous ink composition may further comprise a penetrating agent including the above-mentioned surfactants A and B.
Specific examples of the penetrating agent are anionic surfactants such as polyoxyethylene alkyl ether acetate, and dialkylsulfosuccinate having an alkyl chain with 5 to 7 carbon atoms, which may be branched; nonionic surfactants such as acetylene glycol, polyoxyethylene nonylphenyl ether, and polyoxyethylene alkyl ether; alkyl ethers or aryl ethers derived from polyhydric alcohols such as diethylene glycol monophenyl ether, ethylene glycol monophenyl ether, ethylene glycol monoaryl ether, diethylene glycol monophenyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, and tetraethylene glycol chlorophenyl ether; fluorochemical surfactants; silicone-based surfactants; and lower alcohols such as ethanol and 2-propanol.
With respect to the colorant, the above-mentioned compounds (III) to (V) may be used in combination with other colorants such as water-soluble dyes and pigments when necessary. The water-soluble dyes for use in the present invention, which are divided into the following groups in accordance with the color index number, an acid dye, a direct dye, a basic dye, a reactive dye and a food dye, have water-resistance and light-resistance. Those dyes may be contained in the aqueous ink composition so long as the objects of the present invention are not impaired.
Specific examples of the acid dye and the food dye are as follows:
C.I. Acid Yellow 17, 23, 42, 44, 79, 142;
C.I. Acid Red 1, 8, 13, 14, 18, 26, 27, 35, 37, 42, 52, 82, 87, 89, 92, 97, 106, 111, 114, 115, 134, 186, 249, 254, 289;
C.I. Acid Blue 9, 29, 45, 92, 249;
C.I. Acid Black 1, 2, 7, 24, 26, 94;
C.I. Food Yellow 3, 4;
C.I. Food Red 7, 9, 14; and
C.I. Food Black 1, 2.
Specific examples of the direct dye are as follows:
C.I. Direct Yellow 1, 12, 24, 26, 33, 44, 50, 86, 120, 132, 142, 144;
C.I. Direct Red 1, 4, 9, 13, 17, 20, 28, 31, 39, 80, 81, 83, 89, 225, 227;
C.I. Direct Orange 26, 29, 62, 102;
C.I. Direct Blue 1, 2, 6, 15, 22, 25, 71, 76, 79, 86, 87, 90, 98, 163, 165, 199, 202; and
C.I. Direct Black 19, 22, 32, 38, 51, 56, 71, 74, 75, 77, 154, 168, 171.
Specific examples of the basic dye are as follows:
C.I. Basic Yellow 1, 2, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 40, 41, 45, 49, 51, 53, 63, 64, 65, 67, 70, 73, 77, 87, 91;
C.I. Basic Red 2, 12, 13, 14, 15, 18, 22, 23, 24, 27, 29, 35, 36, 38, 39, 46, 49, 51, 52, 54, 59, 68, 69, 70, 73, 78, 82, 102, 104, 109, 112;
C.I. Basic Blue 1, 3, 5, 7, 9, 21, 22, 26, 35, 41, 45, 47, 54, 62, 65, 66, 67, 69, 75, 77, 78, 89, 92, 93, 105, 117, 120, 122, 124, 129, 137, 141, 147, 155; and
C.I. Basic Black 2, 8.
Specific examples of the reactive dye are as follows:
C.I. Reactive Black 3, 4, 7, 11, 12, 17;
C.I. Reactive Yellow 1, 5, 11, 13, 14, 20, 21, 22, 25, 40, 47, 51, 55, 65, 67;
C.I. Reactive Red 1, 14, 17, 25, 26, 32, 37, 44, 46, 55, 60, 66, 74, 79, 96, 97; and
C.I. Reactive Blue 1, 2, 7, 14, 15, 23, 32, 35, 38, 41, 63, 80, 95.
Examples of the pigment serving as the colorant in the aqueous ink composition of the present invention include organic pigments such as azo pigments, phthalocyanine pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, perylene pigments isoindolenone pigments, Aniline Black, azomethine pigments, Rhodamine B lake pigments, and carbon black; and inorganic pigments such as iron oxide, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, prussian blue, cadmium red, chrome yellow, and metal powder.
In addition, the aqueous ink composition may further comprise a pigment dispersant.
Examples of the pigment dispersant for use in the present invention are natural hydrophobic polymers, for example, vegetable polymers such as gum arabic, tragacanth gum, guar gum, karaya gum, locust bean gum, arabinogalactan, pectin, and quince seed starch; seaweed polymers such as alginic acid, carrageenan, and agar; animal polymers such as gelatin, casein, albumin, and collagen; microbial polymers such as xanthene, and dextran; semisynthetic hydrophobic polymers, for example, cellulose polymers such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose; starch polymers such as starch sodium glycolate, and starch sodium phosphate; and seaweed-based polymers such as sodium alginate, and propyleneglycol alginate; and synthetic hydrophobic polymers, for example, vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, and polyvinyl methyl ether; acrylic resins such as non-crosslinked polyacrylamide, polyacrylic acid and alkali metal salts thereof, and water-soluble styrene-acrylic resin; water-soluble styrene-maleic acid resin; water-soluble vinylnaphthalene-acrylic resin; water-soluble vinylnaphthalene-maleic acid resin; polyvinyl pyrrolidone; polyvinyl alcohol; an alkali metal salt of a condensation product of formalin and β-naphthalene-sulfonic acid; a polymeric compound comprising a salt having a cationic functional group such as quaternary ammonium or amino group on the side chain thereof; and a natural polymeric compound such as shellac wax.
In addition to the above, the aqueous ink composition of the present invention may further comprise conventionally known additives such as an antiseptic agent, a mildewproofing agent, a pH adjustor, a chelate reagent, a corrosion inhibitor and a clogging preventing agent.
For instance, sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, and sodium pentachlorophenol can be employed as the antiseptic agents and mildewproofing agents.
Any materials that is capable of adjusting the obtained aqueous ink composition to pH7 or more without having no adverse effect on the ink composition can freely be employed as the pH adjustors in the present invention.
Examples of the pH adjustor for use in the present invention are amines such as diethanolamine and triethanolamine; hydroxides of alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; other hydroxides such as ammonium hydroxide, quaternary ammonium hydroxide and quaternary phosphonium hydroxide; and carbonates of alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate.
Examples of the chelate reagent for use in the aqueous ink composition of the present invention include sodium ethylene diamine tetraacetate, sodium nitrilotriacetate, sodium hydroxyethyl ethylene diamine triacetate, sodium diethylene triamine pentaacetate, and sodium uramil diacetate.
Examples of the corrosion inhibitor are acid sulfite, sodium thiosulfate, ammon thiodiglycollic acid, diisopropyl ammonium nitrite, pentaerythritol tetranitrate, and dicyclohexyl ammonium nitrite.
Examples of the clogging preventing agent are urea and urea derivatives such as hydroxyethylurea.
Furthermore, the aqueous ink composition of the present invention may further comprise a water-soluble ultraviolet absorbing agent and a water-soluble infrared absorbing agent according to the application of the ink composition.
Other features of this invention will become apparent in the course of the following description of exemplary embodiments, which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLE 1
A mixture of the following components was stirred and dissolved at 80° C.:
______________________________________                                    
                    wt. %                                                 
______________________________________                                    
Colorant:           3                                                     
Mixture of Compound (III-1)                                               
and Compound (III-2)                                                      
2-pyrrolidone       2                                                     
Diethylene glycol   3                                                     
Glycerin            1                                                     
Surfactant A:         0.1                                                 
Compound (I-1)                                                            
Surfactant B: "Nonipol 400"                                               
                      0.5                                                 
(Trademark), made by Sanyo                                                
Chemical Industries, Ltd.                                                 
Ion-exchange water  Balance                                               
______________________________________
The above mixture was cooled to room temperature, and the pH of the mixture was adjusted to the range of 9 to 10 by the addition of 10% aqueous solution of lithium hydroxide. The thus obtained mixture was filtered through a Teflon filter of 0.22 μm, so that an aqueous ink composition No. 1 according to the present invention was obtained.
Using the Sensadyne 6000™ instrument to measure the surface tension by means of air bubble formation inside liquid solution, the surface tension (γ) of the above-prepared aqueous ink composition No. 1 was measured in the bubble frequency (ν) range of 0.5 to 7 Hz at 25° C.
FIG. 1 is a graph which shows the relationship between the surface tension (γ) and the bubble frequency (ν) of the aqueous ink composition No. 1.
As is apparent from the graph of FIG. 1, the following conditions were satisfied:
γ<50 mN/m when ν<1 Hz, and
γ>40 mN/m when ν>5 Hz.
EXAMPLE 2
The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
______________________________________                                    
                    wt. %                                                 
______________________________________                                    
Colorant:           3                                                     
Mixture of Compound (III-1)                                               
and Compound (III-2)                                                      
2-pyrrolidone       4                                                     
Diethylene glycol   3                                                     
Glycerin            1                                                     
Surfactant A:         0.2                                                 
Compound (I-1)                                                            
Surfactant B: "Nonipol 400"                                               
                    1                                                     
(Trademark), made by Sanyo                                                
Chemical Industries, Ltd.                                                 
Sodium dihydroacetate                                                     
                      0.2                                                 
Ion-exchange water  Balance                                               
______________________________________
Thus, an aqueous ink composition No. 2 according to the present invention was obtained.
The surface tension (γ) of the above-prepared aqueous ink composition No. 2 was measured in the same manner as in Example 1.
As a result, the following conditions were satisfied:
γ<50 mN/m when ν<1 Hz, and
γ>40 mN/m when ν>5 Hz.
EXAMPLE 3
The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
______________________________________                                    
                    wt. %                                                 
______________________________________                                    
Colorant:           2.5                                                   
Compound (IV-1)                                                           
Diethylene glycol   6                                                     
Glycerin            2                                                     
Surfactant A:       0.5                                                   
Compound (II-1)                                                           
Surfactant B: "Nonipol 400"                                               
                    0.1                                                   
(Trademark), made by Sanyo                                                
Chemical Industries, Ltd.)                                                
Sodium benzoate     0.2                                                   
Ion-exchange water  Balance                                               
______________________________________
Thus, an aqueous ink composition No. 3 according to the present invention was obtained.
The surface tension (γ) of the above-prepared aqueous ink composition No. 3 was measured in the same manner as in Example 1.
As a result, the following conditions were satisfied:
γ<50 mN/m when ν<1 Hz, and
γ>40 mN/m when ν>5 Hz.
EXAMPLE 4
The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
______________________________________                                    
                    wt. %                                                 
______________________________________                                    
Colorant:             2.5                                                 
Mixture of Compound (V-1)                                                 
and Compound (V-2)                                                        
2-pyrrolidone       6                                                     
Diethylene glycol   3                                                     
Glycerin            1                                                     
Surfactant A:         0.8                                                 
Compound (II-1)                                                           
Surfactant B: "Softanol 300"                                              
                    1                                                     
(Trademark; made by Nippon                                                
Shokubai Co., Ltd.                                                        
Sodium benzoate       0.2                                                 
Ion-exchange water  Balance                                               
______________________________________
Thus, an aqueous ink composition No. 4 according to the present invention was obtained.
The surface tension (γ) of the above-prepared aqueous ink composition No. 4 was measured in the same manner as in Example 1.
As a result, the following conditions were satisfied:
γ<50 mN/m when ν<1 Hz, and
γ>40 mN/m when ν>5 Hz.
EXAMPLE 5
The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the formulation for the ink composition used in Example 1 was changed to the following formulation:
______________________________________                                    
                    wt. %                                                 
______________________________________                                    
Colorant:             2.5                                                 
Mixture of Compound (III-1)                                               
and Compound (III-2)                                                      
2-pyrrolidone       4                                                     
Diethylene glycol   3                                                     
Glycerin            1                                                     
Surfactant A:         0.1                                                 
Compound (I-1)                                                            
Surfactant B: "Nonipol 400"                                               
                    2                                                     
(Trademark), made by Sanyo                                                
Chemical Industries, Ltd.                                                 
Sodium 2-pyridinethiol-1-oxide                                            
                      0.2                                                 
Ion-exchange water  Balance                                               
______________________________________
Thus, an aqueous ink composition No. 5 according to the present invention was obtained.
The surface tension (γ) of the above-prepared aqueous ink composition No. 5 was measured in the same manner as in Example 1.
As a result, the following conditions were satisfied:
γ<50 mN/m when ν<1 Hz, and
γ>40 mN/m when ν>5 Hz.
COMPARATIVE EXAMPLE 1
The procedure for preparation of the aqueous ink composition No. 1 in Example 1 was repeated except that the Compound (I-1) serving as the surfactant A used in the formulation for the ink composition No. 1 in Example 1 was omitted therefrom.
Thus, a comparative aqueous ink composition No. 1 was obtained.
The surface tension (γ) of the above-prepared comparative aqueous ink composition No. 1 was measured in the same manner as in Example 1.
As a result, the previously mentioned conditions were not satisfied.
COMPARATIVE EXAMPLE 2
The procedure for preparation of the aqueous ink composition No. 3 in Example 3 was repeated except that the Compound (II-1) serving as the surfactant A used in the formulation for the ink composition No. 3 in Example 3 was replaced by a commercially available surfactant "BT7" (Trademark), made by Nikko Chemicals Co., Ltd.
Thus, a comparative aqueous ink composition No. 2 was obtained.
The surface tension (γ) of the above-prepared comparative aqueous ink composition No. 2 was measured in the same manner as in Example 1.
As a result, the previously mentioned conditions were not satisfied.
COMPARATIVE EXAMPLE 3
The procedure for preparation of the aqueous ink composition No. 4 in Example 4 was repeated except that a mixture of 2-pyrrolidone in an amount of 6 wt. %, diethylene glycol in an amount of 3 wt. % and glycerin in an amount of 1 wt. % used in the formulation for the ink composition No. 4 in Example 4 was replaced by diethylene glycol monobutyl ether in an amount of 10 wt. %.
Thus, a comparative aqueous ink composition No. 3 was obtained.
The surface tension (γ) of the above-prepared comparative aqueous ink composition No. 3 was measured in the same manner as in Example 1.
As a result, the previously mentioned conditions were not satisfied.
COMPARATIVE EXAMPLE 4
The procedure for preparation of the aqueous ink composition No. 5 in Example 5 was repeated except that the amount of the Compound (I-1) serving as the surfactant A used in the formulation for the ink composition No. 5 in Example 5 was changed from 0.1 wt % to 2 wt. %.
Thus, a comparative aqueous ink composition No. 4 was obtained.
The surface tension (γ) of the above-prepared comparative aqueous ink composition No. 4 was measured in the same manner as in Example 1.
As a result, the previously mentioned conditions were not satisfied.
Using each of the aqueous ink compositions No. 1 to No. 5 according to the present invention and comparative aqueous ink compositions No. 1 to No. 4, the following evaluation tests were conducted.
(1) Measurement of contact angle
Using a commercially available instrument "Kyowa Contact Anglemeter CA-D" (Trademark), made by Kyowa Interface Science Co., Ltd., the contact angle of each aqueous ink composition with respect to a sheet of plain paper "MY PAPER" (trademark), available from NBS Ricoh Co., Ltd., was measured immediately after the ink was dropped on the paper using a micro syringe. Further, the contact angle of each aqueous ink composition with respect to an acrylic resin material constituting the ink flow path was measured 30 seconds after dropping of ink. The measurement was made at 25° C. for both cases.
The results are shown in Table 1.
(2) Image quality
Each ink composition was separately filled into an ink-jet printer having a nozzle with a diameter of 32 μm and a density of 600 dpi. The nozzle was caused to eject the ink composition by the application of pressure thereto at a recording frequency of 12 kHz, utilizing the action of piezoelectric element of PZT of a laminated material.
In this test, printing was conducted on ten kinds of paper, including reclaimed paper, high quality paper and bond paper. By visual inspection from the viewpoints of image blurring, image density, and the density of a solid image, the image quality of the printed ink images was evaluated on the following scale:
∘: good
Δ: slightly poor
x: very poor
The ink deposition amount was about 20 g/m2 in the solid image portion.
The results are shown in Table 1.
(3) Reliability of ink-ejecting performance
The printing operation was continuously carried out without a cleaning sequence of purging, vacuuming and wiping. Then, the printing operation was stopped for 24 hours. When the printing operation was again started after intermission of 24 hours, it was examined whether the weight of an ink droplet ejected from the nozzle was changed or not, and the ejecting direction was deviated or not. The reliability of ink-ejecting performance was evaluated on the following scale:
∘: good
Δ: slightly poor
x: very poor
The results are shown in Table 1.
              TABLE 1                                                     
______________________________________                                    
       Contact                                                            
              Contact                                                     
       Angle (°)                                                   
              Angle (°)   Reliability                              
       vs. Plain                                                          
              vs. Ink    Image   of Ink-                                  
       Paper  Flow Path  Quality Ejection                                 
______________________________________                                    
Ex. 1    45       35         ∘                                
                                   ∘                          
Ex. 2    45       35         ∘                                
                                   ∘                          
Ex. 3    55       45         ∘                                
                                   ∘                          
Ex. 4    50       40         ∘                                
                                   ∘                          
Ex. 5    45       35         ∘                                
                                   ∘                          
Comp.    70       60         Δ                                      
                                   x                                      
Ex. 1                                                                     
Comp.    25       17         x     Δ                                
Ex. 2                                                                     
Comp.    30       30         x     ∘                          
Ex. 3                                                                     
Comp.    30       35         x     ∘                          
Ex. 4                                                                     
______________________________________
In the present invention, the surface tension of the aqueous ink composition is controlled as mentioned above. Therefore, when the aqueous ink composition of the present invention is used for ink-jet printing, the initial ink-loading performance and bubble-discharging performance are excellent due to sufficient wettability of the ink flow path by the ink composition. In addition, when ink images are formed on plain paper using the aqueous ink composition according to the present invention by ink-jet printing method, high quality images can be obtained because of proper penetrating properties of the ink composition into plain paper and wettability of plain paper by the ink composition.
Japanese Patent Application No. 08-132733 filed Apr. 30, 1996, Japanese Patent Application No. 08-184053 filed Jun. 25, 1996, and Japanese Patent Application No. 08-305749 filed Oct. 31, 1996 are hereby incorporated by reference.

Claims (5)

What is claimed is:
1. An aqueous ink composition comprising a colorant, a humectant, surfactant A having a surface tension γA (mN/m) of less than 50 mN/m when a 0.1 wt % aqueous solution of said surfactant A is measured by a maximum bubble pressure method at 25° C. and the bubble frequency νA (Hz) is set at less than 1 Hz, and surfactant B having a surface tension γB (mN/m) of more than 40 mN/m when a 0.1 wt % aqueous solution of said surfactant B is measured by a maximum bubble pressure method at 25° C., and the bubble frequency νB (Hz) is set at less than 1 Hz, wherein said aqueous ink composition has a surface tension γ of less than 50 mN/m when measured by a maximum bubble pressure method at 25° C. with a bubble frequency ν of said aqueous ink composition being set at less than 1 Hz, and a surface tension γ of more than 40 mN/m when measured by said maximum bubble pressure method at 25° C., with said bubble frequency ν of said aqueous ink composition being set at more than 5 Hz.
2. The aqueous ink composition as claimed in claim 1, wherein said surfactant A is selected from the group consisting of a polyoxyethylene alkyl ether acetate of formula (I):
R.sup.1 --O--(CH.sub.2 CH.sub.2 O).sub.m --CH.sub.2 COOM   (I)
wherein R1 is an alkyl group having 6 to 14 carbon atoms, which may be branched; m is an integer of 3 to 12, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation; and a dialkyl sulfosuccinate of formula (II): ##STR10## wherein R2 is an alkyl group having 5 to 7 carbon atoms, which may be branched, and M is a cation selected from the group consisting of alkali metal ion, quaternary ammonium cation, quaternary phosphonium cation and alkanol amine cation.
3. The aqueous ink composition as claimed in claim 2, wherein said surfactant A is in an amount of 0.05 to 1.0 wt. % of the total weight of said aqueous ink composition.
4. The aqueous ink composition as claimed in claim 1, wherein said surfactant B is a nonionic surfactant.
5. The aqueous ink composition as claimed in claim 4, wherein said surfactant B is in an amount of 0.05 to 5.0 wt. % of the total weight of said aqueous ink composition.
US08/848,192 1996-04-30 1997-04-29 Aqueous ink composition and ink-jet printing method using the same Expired - Lifetime US5972082A (en)

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JP18405396A JP3573878B2 (en) 1996-06-25 1996-06-25 Aqueous ink and ink jet recording method using the ink
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US6613136B1 (en) 1999-09-17 2003-09-02 Ricoh Company, Ltd. Recording ink composition and ink-jet printing method using the same
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US6695443B2 (en) 2001-05-29 2004-02-24 Ricoh Company, Ltd. Ink for ink jet recording, ink set for ink jet recording, method for ink jet recording, ink cartridge for ink jet recording, ink jet recording apparatus and recorded article
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US20040123366A1 (en) * 2002-12-27 2004-07-01 Schorr Phillip A. Anti-wicking protective workwear and methods of making and using same
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US20070097155A1 (en) * 2005-10-28 2007-05-03 Canon Kabushiki Kaisha Aqueous ink, ink jet recording method, ink cartridge, recording unit and ink jet recording apparatus
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US8608306B2 (en) 2009-03-06 2013-12-17 Ricoh Company, Ltd. Inkjet recording ink, ink cartridge, inkjet recording apparatus, and ink recorded matter
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Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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US8784549B2 (en) * 2011-09-16 2014-07-22 Eastman Kodak Company Ink set for continuous inkjet printing
US10500145B2 (en) 2015-06-19 2019-12-10 inkbox ink Inc. Body ink compositions and applicators

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4647310A (en) * 1985-02-26 1987-03-03 Ricoh Company, Ltd. Aqueous ink composition for ink jet-recording
US4711668A (en) * 1985-04-17 1987-12-08 Ricoh Company, Ltd. Aqueous ink composition
US4793860A (en) * 1986-04-02 1988-12-27 Ricoh Company, Ltd. Aqueous ink composition
US5389131A (en) * 1992-12-17 1995-02-14 Xerox Corporation Ink compositions and preparation processes thereof
US5431720A (en) * 1992-10-01 1995-07-11 Ricoh Company, Ltd. Aqueous ink composition and ink-jet printing method using the same
US5514208A (en) * 1993-12-22 1996-05-07 Ricoh Company, Ltd. Aqueous ink and method for recording image with the aqueous ink
US5554213A (en) * 1992-12-17 1996-09-10 Xerox Corporation Ink compositions for ink jet printing
US5696182A (en) * 1993-03-15 1997-12-09 Canon Kabushiki Kaisha Ink, ink-jet recording process making use of the ink, and apparatus using the ink
US5769930A (en) * 1995-10-06 1998-06-23 Seiko Epson Corporation Ink composition for ink jet recording and recording process using same

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5604276A (en) * 1989-01-07 1997-02-18 Canon Kabushiki Kaisha Recording liquid and method for ink jet recording using same
US5428383A (en) * 1992-08-05 1995-06-27 Hewlett-Packard Corporation Method and apparatus for preventing color bleed in a multi-ink printing system
US5451251A (en) * 1993-02-26 1995-09-19 Canon Kabushiki Kaisha Ink, and ink-jet recording method and instrument using the same
JP3574236B2 (en) * 1995-10-06 2004-10-06 セイコーエプソン株式会社 Recording medium having ink receiving layer
WO1997046623A1 (en) * 1996-06-05 1997-12-11 Basf Aktiengesellschaft Dye preparations
US5833744A (en) * 1997-01-13 1998-11-10 Xerox Corporation Waterfast ink jet inks containing a surfactant
JPH10291365A (en) * 1997-04-21 1998-11-04 Fuji Xerox Co Ltd Multicolor ink set and ink jet recording method
US6120589A (en) * 1998-02-20 2000-09-19 Ricoh Company, Ltd. Set of color ink compositions for ink-jet printing and method of forming color images using the color ink set

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4647310A (en) * 1985-02-26 1987-03-03 Ricoh Company, Ltd. Aqueous ink composition for ink jet-recording
US4711668A (en) * 1985-04-17 1987-12-08 Ricoh Company, Ltd. Aqueous ink composition
US4793860A (en) * 1986-04-02 1988-12-27 Ricoh Company, Ltd. Aqueous ink composition
US5431720A (en) * 1992-10-01 1995-07-11 Ricoh Company, Ltd. Aqueous ink composition and ink-jet printing method using the same
US5389131A (en) * 1992-12-17 1995-02-14 Xerox Corporation Ink compositions and preparation processes thereof
US5554213A (en) * 1992-12-17 1996-09-10 Xerox Corporation Ink compositions for ink jet printing
US5696182A (en) * 1993-03-15 1997-12-09 Canon Kabushiki Kaisha Ink, ink-jet recording process making use of the ink, and apparatus using the ink
US5514208A (en) * 1993-12-22 1996-05-07 Ricoh Company, Ltd. Aqueous ink and method for recording image with the aqueous ink
US5769930A (en) * 1995-10-06 1998-06-23 Seiko Epson Corporation Ink composition for ink jet recording and recording process using same

Cited By (92)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6613136B1 (en) 1999-09-17 2003-09-02 Ricoh Company, Ltd. Recording ink composition and ink-jet printing method using the same
US6264731B1 (en) * 1999-11-29 2001-07-24 Xerox Corporation Ink compositions containing 1,3,5-trioxane or tetraethylene glycol dimethyl ether
US6730155B2 (en) 2000-06-30 2004-05-04 Ricoh Company, Ltd. Aqueous ink composition
US20040067202A1 (en) * 2000-09-22 2004-04-08 Looker Brian Edgar Novel alkanoic acid derivaties
US7217409B2 (en) 2000-09-22 2007-05-15 Smithkline Beecham Corporation Alkanoic acid derivatives
WO2002024623A3 (en) * 2000-09-22 2003-02-20 Glaxo Group Ltd Novel alkanoic acid derivatives
US6688737B2 (en) 2000-12-05 2004-02-10 Ricoh Company, Ltd. Recording liquid, inkjet recording method and recording equipment using the same
US6799845B2 (en) 2000-12-07 2004-10-05 Ricoh Company, Ltd. Recording liquid, recording cartridge, recording method, recording apparatus and recording medium
US20040046846A1 (en) * 2000-12-20 2004-03-11 Alessandra Pistagna Ink for thermal ink jet printing with high performance at high ejection frequencies
US7160373B2 (en) 2000-12-20 2007-01-09 Telecom Italia S.P.A. Ink for thermal ink jet printing with high performance at high ejection frequencies
US6926766B2 (en) 2000-12-20 2005-08-09 Olivetti Technost S.P.A. Ink for thermal ink jet printing with high performance at high ejection frequencies
WO2002050198A1 (en) * 2000-12-20 2002-06-27 Olivetti Tecnost S.P.A. Ink for thermal ink jet printing with high performance at high ejection frequencies
US20050204954A1 (en) * 2000-12-20 2005-09-22 Olivetti Tecnost S.P.A. Ink for thermal ink jet printing with high performance at high ejection frequencies
US6918662B2 (en) 2001-01-22 2005-07-19 Ricoh Company Limited Ink composition and inkjet recording method and apparatus using the ink composition
US6730149B2 (en) 2001-01-22 2004-05-04 Ricoh Company Limited Ink composition and inkjet recording method and apparatus using the ink composition
US20040179066A1 (en) * 2001-01-22 2004-09-16 Ricoh Company Limited Ink composition and inkjet recording method and apparatus using the ink composition
EP1236778A1 (en) * 2001-03-02 2002-09-04 Hewlett-Packard Company Inkjet ink having improved directionality by controlling surface tension and wetting properties
US6478418B2 (en) 2001-03-02 2002-11-12 Hewlett-Packard Company Inkjet ink having improved directionality by controlling surface tension and wetting properties
US6578958B2 (en) 2001-03-22 2003-06-17 Ricoh Company, Ltd. Inkjet recording method and apparatus and ink therefor
US20050007431A1 (en) * 2001-03-23 2005-01-13 Masayuki Koyano Pretreatment liquid for recording material and image recording method using the pretreatment liquid
US6637875B2 (en) 2001-03-23 2003-10-28 Ricoh Company, Ltd. Aqueous recording liquid, recording method and apparatus using same
US6786588B2 (en) 2001-03-23 2004-09-07 Ricoh Company Limited Pretreatment liquid for recording material and image recording method using the pretreatment liquid
US7033013B2 (en) 2001-03-23 2006-04-25 Ricoh Company Limited Pretreatment liquid for recording material and image recording method using the pretreatment liquid
US6572227B2 (en) * 2001-05-09 2003-06-03 Fuji Zerox Co., Ltd. Ink-jet recording method and ink-jet recording apparatus
US6695443B2 (en) 2001-05-29 2004-02-24 Ricoh Company, Ltd. Ink for ink jet recording, ink set for ink jet recording, method for ink jet recording, ink cartridge for ink jet recording, ink jet recording apparatus and recorded article
US20080273045A1 (en) * 2001-09-02 2008-11-06 Naoya Morohoshi Ink Jet Recording Method, Recording Device, Ink/Recording Medium Set, Recording Matter
US8118419B2 (en) 2001-09-20 2012-02-21 Ricoh Company, Ltd. Ink jet recording method, recording device, ink/recording medium set, recording matter
US20050007433A1 (en) * 2001-09-21 2005-01-13 Tomohiro Inoue Ink, method of ink-jet recording with the same, ink cartridge, recording unit, and ink-jet recording apparatus
US7370952B2 (en) 2001-09-21 2008-05-13 Ricoh Company, Ltd. Ink, and, inkjet recording process, ink cartridge, recording unit, and inkjet recording apparatus using the ink
US7097698B2 (en) * 2002-03-05 2006-08-29 Matsushita Electric Industrial Co., Ltd. Ink-jet recording ink, ink cartridge and recording device using such ink
US20030197769A1 (en) * 2002-03-05 2003-10-23 Mamoru Soga Ink-jet recording ink, ink cartridge and recording device using such ink
US7250077B2 (en) * 2002-05-29 2007-07-31 Matsushita Electric Industrial Co., Ltd. Ink composition for inkjet recording, ink cartridge and recording apparatus
US20030221586A1 (en) * 2002-05-29 2003-12-04 Hidekazu Arase Ink composition for inkjet recording, ink cartridge and recording apparatus
CN1305979C (en) * 2002-05-29 2007-03-21 松下电器产业株式会社 Ink composite for ink-jet recording, cartridge and recording device
US20040069183A1 (en) * 2002-09-18 2004-04-15 Sharp Kabushiki Kaisha Ink composition, recording method and recorded image utilizing the same, ink set and ink head
US7699919B2 (en) 2002-09-18 2010-04-20 Sharp Kabushiki Kaisha Ink composition, recording method and recorded image utilizing the same, ink set and ink head
US20040066432A1 (en) * 2002-10-04 2004-04-08 Shigeo Hatada Ink mixing device, ink manufacturing apparatus, method for washing the ink manufacturing apparatus, method for manufacturing ink, ink, ink cartridge containing the ink, image forming method and apparatus using the ink, and print image produced by the image forming method and apparatus
US6863386B2 (en) 2002-10-04 2005-03-08 Ricoh Company Limited Ink mixing device, ink manufacturing apparatus, method for washing the ink manufacturing apparatus, method for manufacturing ink, ink, ink cartridge containing the ink, image forming method and apparatus using the ink, and print image produced by the image forming method and apparatus
US20060011703A1 (en) * 2002-11-06 2006-01-19 Hitoshi Arita Solder alloy material layer composition, electroconductive and adhesive composition, flux material layer composition, solder ball transferring sheet, bump and bump forming process, and semiconductore device
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US7847406B2 (en) 2002-11-06 2010-12-07 Ricoh Company, Ltd. Solder alloy material layer composition, electroconductive and adhesive composition, flux material layer composition, solder ball transferring sheet, bump and bump forming process, and semiconductore device
US7155746B2 (en) 2002-12-27 2007-01-02 Kimberly-Clark Worldwide, Inc. Anti-wicking protective workwear and methods of making and using same
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US20040123366A1 (en) * 2002-12-27 2004-07-01 Schorr Phillip A. Anti-wicking protective workwear and methods of making and using same
US7943813B2 (en) 2002-12-30 2011-05-17 Kimberly-Clark Worldwide, Inc. Absorbent products with enhanced rewet, intake, and stain masking performance
US7222948B2 (en) 2003-04-18 2007-05-29 Ricoh Company, Ltd. Liquid containing bag, liquid cartridge, image forming device and sealing method and sealing apparatus for the liquid containing bag
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US9901492B2 (en) 2003-07-18 2018-02-27 Kimberly-Clark Worldwide, Inc. Absorbent article with high quality ink jet image produced at line speed
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US8273066B2 (en) 2003-07-18 2012-09-25 Kimberly-Clark Worldwide, Inc. Absorbent article with high quality ink jet image produced at line speed
US7169217B2 (en) * 2003-08-28 2007-01-30 Konica Minolta Holdings, Inc. Ink and ink-jet recording method using the same
EP1512731A1 (en) * 2003-08-28 2005-03-09 Konica Minolta Holdings, Inc. Ink and ink-jet recording method using the same
US20050045062A1 (en) * 2003-08-28 2005-03-03 Konica Minolta Holdings, Inc. Ink and ink-jet recording method using the same
US20070097155A1 (en) * 2005-10-28 2007-05-03 Canon Kabushiki Kaisha Aqueous ink, ink jet recording method, ink cartridge, recording unit and ink jet recording apparatus
US8324293B2 (en) * 2005-10-28 2012-12-04 Canon Kabushiki Kaisha Aqueous ink, ink jet recording method, ink cartridge, recording unit and ink jet recording apparatus
US7988277B2 (en) * 2007-05-11 2011-08-02 Canon Kabushiki Kaisha Ink set, ink jet recording method, ink cartridge, recording unit, ink jet recording method, and aqueous ink
US7976146B2 (en) 2007-05-11 2011-07-12 Canon Kabushiki Kaisha Ink jet recording ink tank
EP1990200A3 (en) * 2007-05-11 2010-09-15 Canon Kabushiki Kaisha Ink jet recording ink tank
US20080280043A1 (en) * 2007-05-11 2008-11-13 Canon Kabushiki Kaisha Ink set, ink jet recording method, ink cartridge, recording unit, ink jet recording method, and aqueous ink
US7682433B2 (en) 2007-05-11 2010-03-23 Canon Kabushiki Kaisha Ink set, ink jet recording method, ink cartridge, recording unit, and ink jet recording apparatus
US20080278552A1 (en) * 2007-05-11 2008-11-13 Canon Kabushiki Kaisha Ink jet recording ink tank
US20080280042A1 (en) * 2007-05-11 2008-11-13 Canon Kabushiki Kaisha Ink set, ink jet recording method, ink cartridge, recording unit, and ink jet recording apparatus
US20100194837A1 (en) * 2009-02-02 2010-08-05 Tohru Ohshima Image recording method
US8201935B2 (en) 2009-02-02 2012-06-19 Ricoh Company, Limited Image recording method
US8608306B2 (en) 2009-03-06 2013-12-17 Ricoh Company, Ltd. Inkjet recording ink, ink cartridge, inkjet recording apparatus, and ink recorded matter
US8845091B2 (en) 2009-03-18 2014-09-30 Ricoh Company, Ltd. Variable printing medium having high glossiness, and recording method
US8746869B2 (en) 2009-06-23 2014-06-10 Ricoh Company, Ltd. Ink for inkjet recording, inkjet recording method using the same, ink cartridge housing the same, and recorded matter
US8752948B2 (en) 2010-03-02 2014-06-17 Ricoh Company, Ltd. Inkjet recording ink containing fluorine based surfactant, inkjet recording ink set, and inkjet recording apparatus containing the inkjet recording ink
US20110216123A1 (en) * 2010-03-02 2011-09-08 Takashi Tamai Inkjet recording ink containing fluorine based surfactant, inkjet recording ink set, and inkjet recording apparatus containing the inkjet recording ink
US9034091B2 (en) 2010-03-05 2015-05-19 Ricoh Company, Ltd. Inkjet recording ink set, inkjet recording method, and recorded matter
US8815140B2 (en) 2010-04-09 2014-08-26 Ricoh Company, Ltd. Method of producing film by inkjet process, and film
US9518190B2 (en) 2010-08-04 2016-12-13 Ricoh Company, Ltd. Inkjet ink, ink cartridge, inkjet recording method, inkjet recording device, and inkjet recorded matter
US9085706B2 (en) 2010-08-04 2015-07-21 Ricoh Company, Ltd. Inkjet ink, ink cartridge, inkjet recording method, inkjet recording device, and inkjet recorded matter
US8980408B2 (en) 2010-08-19 2015-03-17 Ricoh Company, Ltd. Liquid composition, recording method, and recorded matter
US8708475B2 (en) 2010-12-14 2014-04-29 Ricoh Company, Ltd. Ultraviolet crosslinking inkjet ink, ink cartridge containing same, and image forming method and apparatus using same
US8727522B2 (en) 2011-01-04 2014-05-20 Ricoh Company, Ltd. Ultraviolet crosslinking ink and inkjet recording method
US8740374B2 (en) 2011-03-25 2014-06-03 Ricoh Company, Ltd. Ink jet recording method, ink jet recording apparatus, and ink jet recorded matter
US9879207B2 (en) 2012-02-01 2018-01-30 Ricoh Company, Ltd. Cleaning filling liquid, cartridge, cleaning filling method, and inkjet recording device
US8979255B2 (en) 2012-03-14 2015-03-17 Ricoh Company, Ltd. Ink cartridge and method of replenishing ink cartridge
US9217092B2 (en) 2012-05-16 2015-12-22 Ricoh Company, Ltd. Inkjet recording method, inkjet recording device, and ink recorded matter
US9279060B2 (en) 2012-11-29 2016-03-08 Seiko Epson Corporation Ink composition, ink jet recording apparatus, and ink jet recording system
US8899719B2 (en) 2013-01-07 2014-12-02 Ricoh Company, Ltd. Image forming method and image forming apparatus
US9505234B2 (en) 2013-01-10 2016-11-29 Ricoh Company, Ltd. Inkjet recording method and inkjet recording device
US8899711B2 (en) 2013-03-06 2014-12-02 Ricoh Company, Ltd. Inkjet recording method, inkjet recording device, and recorded material
US20190177497A1 (en) * 2017-10-11 2019-06-13 Molecular Rebar Design, Llc Mixtures of discrete carbon nanotubes
US11053362B2 (en) * 2017-10-11 2021-07-06 Molecular Rebar Design, Llc Mixtures of discrete carbon nanotubes
US12410057B2 (en) 2017-10-11 2025-09-09 Molecular Rebar Design, Llc Mixtures of discrete carbon nanotubes

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